If you want to save vertical space, you can place the basket outside the UDS just beneath the bottom, a combination of a kamado fire pot and ash collect on a Weber. flange of ash collector sits on the bottom of USD. Flange of fire box sits on the ash collector. You can pull out of basket/ ash collector from USD.
Certainly you need to add 3 legs on your USD
on the air inlet you can attach a fan via my fan adapter C, the thread type